Grade curve calculator
Paste a list of test scores and pick a curve. You'll see each student's curved score, the new letter grade and the new class average. Useful for teachers, and for students wondering what a curve will do.
- Free, no sign-up
- Works for US, Canada & Australia
- Private: grades stay on your device
Four ways to curve grades
| Method | How it works | 72% becomes |
|---|---|---|
| Flat (top = 100) | Add the gap between the top score and 100 to everyone. Top score 88 means +12. | 84% |
| Scale | Multiply every score by 100 ÷ top score. Top 88 means × 1.136. | 81.8% |
| Square root | New score = 10 × √score | 84.9% |
| Target average | Add the gap between the current and the target average. Average 75, target 80 means +5. | 77% |
Curved scores are capped at 100%.
Do colleges curve grades?
Many large intro courses in science, engineering and economics curve exams so the average lands near a B- or C+. Ask your instructor which method they use, then try it here with your own score to see what to expect.
Frequently asked questions
What does it mean to curve a grade?
Curving raises scores after a test that turned out harder than intended. The teacher adds points or rescales the scores so the results better match what students know.
What is a flat curve?
Every score goes up by the same number of points, usually enough to bring the highest score to 100%.
How does the square root curve work?
Each score becomes 10 times its square root. A 64 becomes 80 and an 81 becomes 90. Low scores rise much more than high scores.
Can a curve lower my grade?
The methods here never lower a score. Bell-curve grading (assigning a fixed share of As and Bs) can, but few classes use it today.
Which curve is fairest?
A flat curve keeps the gaps between students the same. A square root curve helps struggling students most. Setting a target average is common in college.